[v9,00/34] Add subcluster allocation to qcow2

Hi,

here's the new version of the patches to add subcluster allocation
support to qcow2.

Please refer to the cover letter of the first version for a full
description of the patches:

   https://lists.gnu.org/archive/html/qemu-block/2019-10/msg00983.html

The important change from v8 is patch 24. This patch fixes unaligned
offsets in ZERO_ALLOC clusters, but the previous implementation was
not working for images with extended L2 entries and was simply adding
dead code. The new implementation works properly.

If you want to test this series make sure to apply this patch first:

   https://lists.gnu.org/archive/html/qemu-block/2020-06/msg00504.html

Berto

Based-on: <20200610094600.4029-1-berto@igalia.com>

v9:
- Patch 24: Change the algorithm so it actually does something in
  images with extended L2 entries.
- Patch 31: Update expected test results after rebase
- Patch 34: Fix a couple of typos.
            Add a new test for the changes in patch 24.
            Test concurrent requests on different subclusters of the
            same cluster.

v8: https://lists.gnu.org/archive/html/qemu-block/2020-06/msg00546.html
v7: https://lists.gnu.org/archive/html/qemu-block/2020-05/msg01683.html
v6: https://lists.gnu.org/archive/html/qemu-block/2020-05/msg01583.html
v5: https://lists.gnu.org/archive/html/qemu-block/2020-05/msg00251.html
v4: https://lists.gnu.org/archive/html/qemu-block/2020-03/msg00966.html
v3: https://lists.gnu.org/archive/html/qemu-block/2019-12/msg00587.html
v2: https://lists.gnu.org/archive/html/qemu-block/2019-10/msg01642.html
v1: https://lists.gnu.org/archive/html/qemu-block/2019-10/msg00983.html

Output of git backport-diff against v8:

Key:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively

001/34:[----] [--] 'qcow2: Make Qcow2AioTask store the full host offset'
002/34:[----] [--] 'qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset()'
003/34:[----] [--] 'qcow2: Add calculate_l2_meta()'
004/34:[----] [--] 'qcow2: Split cluster_needs_cow() out of count_cow_clusters()'
005/34:[----] [--] 'qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied()'
006/34:[----] [--] 'qcow2: Add get_l2_entry() and set_l2_entry()'
007/34:[----] [--] 'qcow2: Document the Extended L2 Entries feature'
008/34:[----] [--] 'qcow2: Add dummy has_subclusters() function'
009/34:[----] [--] 'qcow2: Add subcluster-related fields to BDRVQcow2State'
010/34:[----] [--] 'qcow2: Add offset_to_sc_index()'
011/34:[----] [--] 'qcow2: Add offset_into_subcluster() and size_to_subclusters()'
012/34:[----] [--] 'qcow2: Add l2_entry_size()'
013/34:[----] [--] 'qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap()'
014/34:[----] [--] 'qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type()'
015/34:[----] [--] 'qcow2: Add qcow2_get_subcluster_range_type()'
016/34:[----] [--] 'qcow2: Add qcow2_cluster_is_allocated()'
017/34:[----] [--] 'qcow2: Add cluster type parameter to qcow2_get_host_offset()'
018/34:[----] [--] 'qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_*'
019/34:[----] [--] 'qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC'
020/34:[----] [--] 'qcow2: Add subcluster support to calculate_l2_meta()'
021/34:[----] [--] 'qcow2: Add subcluster support to qcow2_get_host_offset()'
022/34:[----] [--] 'qcow2: Add subcluster support to zero_in_l2_slice()'
023/34:[----] [--] 'qcow2: Add subcluster support to discard_in_l2_slice()'
024/34:[0025] [FC] 'qcow2: Add subcluster support to check_refcounts_l2()'
025/34:[----] [--] 'qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2()'
026/34:[----] [--] 'qcow2: Clear the L2 bitmap when allocating a compressed cluster'
027/34:[----] [--] 'qcow2: Add subcluster support to handle_alloc_space()'
028/34:[----] [--] 'qcow2: Add subcluster support to qcow2_co_pwrite_zeroes()'
029/34:[----] [--] 'qcow2: Add subcluster support to qcow2_measure()'
030/34:[----] [--] 'qcow2: Add prealloc field to QCowL2Meta'
031/34:[0004] [FC] 'qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit'
032/34:[----] [--] 'qcow2: Allow preallocation and backing files if extended_l2 is set'
033/34:[----] [--] 'qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters'
034/34:[0152] [FC] 'iotests: Add tests for qcow2 images with extended L2 entries'

Alberto Garcia (34):
  qcow2: Make Qcow2AioTask store the full host offset
  qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset()
  qcow2: Add calculate_l2_meta()
  qcow2: Split cluster_needs_cow() out of count_cow_clusters()
  qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied()
  qcow2: Add get_l2_entry() and set_l2_entry()
  qcow2: Document the Extended L2 Entries feature
  qcow2: Add dummy has_subclusters() function
  qcow2: Add subcluster-related fields to BDRVQcow2State
  qcow2: Add offset_to_sc_index()
  qcow2: Add offset_into_subcluster() and size_to_subclusters()
  qcow2: Add l2_entry_size()
  qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap()
  qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type()
  qcow2: Add qcow2_get_subcluster_range_type()
  qcow2: Add qcow2_cluster_is_allocated()
  qcow2: Add cluster type parameter to qcow2_get_host_offset()
  qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_*
  qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC
  qcow2: Add subcluster support to calculate_l2_meta()
  qcow2: Add subcluster support to qcow2_get_host_offset()
  qcow2: Add subcluster support to zero_in_l2_slice()
  qcow2: Add subcluster support to discard_in_l2_slice()
  qcow2: Add subcluster support to check_refcounts_l2()
  qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2()
  qcow2: Clear the L2 bitmap when allocating a compressed cluster
  qcow2: Add subcluster support to handle_alloc_space()
  qcow2: Add subcluster support to qcow2_co_pwrite_zeroes()
  qcow2: Add subcluster support to qcow2_measure()
  qcow2: Add prealloc field to QCowL2Meta
  qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit
  qcow2: Allow preallocation and backing files if extended_l2 is set
  qcow2: Assert that expand_zero_clusters_in_l1() does not support
    subclusters
  iotests: Add tests for qcow2 images with extended L2 entries

 docs/interop/qcow2.txt           |  68 ++-
 docs/qcow2-cache.txt             |  19 +-
 qapi/block-core.json             |   7 +
 block/qcow2.h                    | 211 ++++++-
 include/block/block_int.h        |   1 +
 block/qcow2-cluster.c            | 912 +++++++++++++++++++++----------
 block/qcow2-refcount.c           |  47 +-
 block/qcow2.c                    | 304 +++++++----
 block/trace-events               |   2 +-
 tests/qemu-iotests/031.out       |   8 +-
 tests/qemu-iotests/036.out       |   4 +-
 tests/qemu-iotests/049.out       | 102 ++--
 tests/qemu-iotests/060.out       |   3 +-
 tests/qemu-iotests/061           |   6 +
 tests/qemu-iotests/061.out       |  25 +-
 tests/qemu-iotests/065           |  12 +-
 tests/qemu-iotests/082.out       |  48 +-
 tests/qemu-iotests/085.out       |  38 +-
 tests/qemu-iotests/144.out       |   4 +-
 tests/qemu-iotests/182.out       |   2 +-
 tests/qemu-iotests/185.out       |   8 +-
 tests/qemu-iotests/198.out       |   2 +
 tests/qemu-iotests/206.out       |   6 +-
 tests/qemu-iotests/242.out       |   5 +
 tests/qemu-iotests/255.out       |   8 +-
 tests/qemu-iotests/271           | 901 ++++++++++++++++++++++++++++++
 tests/qemu-iotests/271.out       | 724 ++++++++++++++++++++++++
 tests/qemu-iotests/274.out       |  49 +-
 tests/qemu-iotests/280.out       |   2 +-
 tests/qemu-iotests/291.out       |   6 +-
 tests/qemu-iotests/common.filter |   1 +
 tests/qemu-iotests/group         |   1 +
 32 files changed, 2963 insertions(+), 573 deletions(-)
 create mode 100755 tests/qemu-iotests/271
 create mode 100644 tests/qemu-iotests/271.out